Meningococcal disease remains an important public health burden worldwide a
nd, indeed, cause of death, particularly in poorer countries. The rapidly p
rogressive nature of infections means that antibiotic therapy often comes t
oo late. Vaccines are of limited efficacy in infants, one of the most vulne
rable age groups, and do not exist for bacteria of serogroup B. Hence, much
remains to be achieved in terms of vaccine design and the understanding of
the pathogenesis of meningococcal disease. The causative bacterium, Neisse
ria meningitidis, is usually a commensal of the nasopharynx, factors that l
ead to the invasion of the bloodstream, often followed by the crossing of t
he blood-brain barrier and meningitis, may be partly host-and partly bacter
ium-dependent, but are ill-understood. It is hoped that. taken together wit
h the fundamental knowledge gained from biochemical and genetic studies, th
e huge amount of new information made available with the recent publication
of the genome sequences will help to unlock more of the secrets of the lif
estyle and pathogenic potential of this still poorly understood pathogen.